Development of a mutant of Trichoderma citrinoviride for enhanced production of cellulases.
Considering importance of a microbial strain capable of increased cellulases production and insensitive to catabolite repression for industrial use, we have developed a mutant strain of Trichoderma citrinoviride by multiple exposures to EMS and ethidium bromide. The mutant produced 0.63, 3.12, 8.22 and 1.94 IU ml(-1) FPase, endoglucanase, beta-glucosidase and cellobiase, respectively. These levels were, respectively, 2.14, 2.10, 4.09 and 1.73 fold higher than those in parent strain. Glucose (upto 20 mM) did not repress enzyme production by the mutant under submerged fermentation conditions. In vitro activity assay with partially purified cellulase showed lack of inhibition by glucose. Interestingly, the partially purified endoglucanase and beta-glucosidase were activated by 2.0 fold and 2.6 fold, respectively, by 20 mM and 30 mM ethanol in the assay mixture. Genetic distinction of the mutant was revealed by the presence of two unique amplicans in comparative DNA fingerprinting performed using 20 random primers.
Chandra
Mahesh
M
Division of Field Laboratories and Organic Farming, Central Institute of Medicinal and Aromatic Plants, Lucknow-226015, UP, India.
Kalra
Alok
A
Sangwan
Neelam S
NS
Gaurav
Shailendra S
SS
Darokar
Mahender P
MP
Sangwan
Rajinder S
RS
D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates; D044602:Cellulases / Q000096:biosynthesis* / Q000302:isolation & purification; D016172:DNA Fingerprinting; D000431:Ethanol / Q000494:pharmacology; D005285:Fermentation / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D016296:Mutagenesis / Q000187:drug effects; D009154:Mutation / Q000235:genetics*; D014242:Trichoderma / Q000187:drug effects / Q000201:enzymology*
D002241:Carbohydrates; D000431:Ethanol; D044602:Cellulases; D005947:Glucose